The present invention relates to compensation of communications when different satellite systems overlap with one another.
Satellite systems require communication between a base station on the ground, and a satellite in orbit. The base station on the ground needs to track the satellite in order to receive and transmit the information to the satellite.
As more and more satellites are used in low earth orbits, a possibility occurs that two satellites will interfere with one another.
Two satellites can interfere when both enter the main beam of the same base station. When the two satellites coalesce at the same point on the same frequency, they will interfere with one another, and could interrupt or degrade transmissions to one or both of the satellites.
The normal expectation in the art and normal operation in practice is that the center line of a beam from a base station should point directly at the center line of the satellite. This would provide perfect tracking of the satellite. However, the inventor recognized that the satellite can still be tracked and communication can continue, so long as the tracking with one""s own satellite is within a zone. That zone is defined by the characteristics of the antenna that is transmitting and receiving.
According to an embodiment, characteristics of the feeder antenna are determined. Typically, the spatial characteristics of the feeder antenna have a predetermined waveform which has nulls therein which define areas of lower antenna gain. According to this embodiment, the desired satellite is steered to a position in the beam which is offset from the center of the beam but which puts the undesired satellite as close to a null as possible. This is done by two dimensional steering of the beam away from the center point of the satellite, i.e., steering in azimuth and elevation.